QuestionCan you tell me where the speedometer gears are located? My husband took out the dash and found what he thinks is the module that controls the odometer. It had a sticker on it that said Do Not Open, but of course, he did. All that was inside was a circuit board. Thanks!
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Followup To
Question -
My dad has a 1989 Lincoln Mark VII. The odometer has recently started showing the word error. He doesn't want to put a lot of money into the car but needs to have this corrected in order to pass inspection. Any suggestions?
Answer -
Hi Susan,
Well, that error on the odometer read out indicates a broken gear in the speedometer head. A couple ways to do this, one; new from Ford, part number E8LY17255A for about $218 or go to a wrecking yard and try to find on. The book calls for 1.1 hours to install. I'm afraid the second option may be like a needle in a haystack. A third way would to be to take the car down to someone that specializes in speedo's (not the swimwear) if you don't want to DIY and have them fix it. These guys are pretty good and usually can recall the correct milage on the car. The odometer works in conjunction with the speedometer. You didn't mention if the speedo was working or not so I am assuming that it does. If the speedo is also in-op then we have a bunch more to talk about. Hope this helps!
AnswerAh, I gave you some wrong info, I was thinking how the analog speedo/odometer works. Sorry, yours is fully electronic. Here is a couple of Technical Service Bulletins on this. Please read them in full and I have notes below and at the bottom, the correct part number.
SPEEDOMETER - MECHANICAL/ELECTRONIC - INACCURATE SPEED READINGS AND ODOMETER READINGS
Article No.
89-2-7
FORD:
1989 AND PRIOR ALL CAR LINES
LINCOLN-MERCURY:
1989 AND PRIOR ALL CAR LINES
LIGHT TRUCK:
1989 AND PRIOR ALL TRUCK LINES
ISSUE:
The accuracy of speedometer/odometer readings may be influenced by several vehicle components or systems. The information in this TSB article is intended to assist technicians in speedometer/odometer concern diagnosis.
ACTION:
Use the following supplemental information below to assist in speedometer/odometer diagnostics.
OPERATION
A mechanical analog speedometer displays vehicle speed and the odometer displays total distance traveled. The speedometer/odometer assembly is cable driven by either a transmission or a transaxle. All speedometer/odometer assemblies, except for police vehicles are the same with respect to the speed accuracy tolerance used during calibration. The odometer gear ratio is fixed so that all are identical and have no error in the speedometer head.
Electronic digital operation is similar. It could use a drive cable or a speed sensor to drive the speedometer/odometer. An electronic signal is sent from a speed sensor to the digital speedometer/ odometer assembly. The speed sensor is driven by a transmission or a transaxle, similar to a cable.
Several areas of concern that may affect speedometer/ odometer readings are tires, axle gear ratio and speedometer/odometer drive and driven gears.
TIRES
Improper tire rolling radius and inflation pressure, temperature and size may contribute to inaccurate system readings. System accuracy testing should be performed after the tires are set at the correct pressure as shown on the safety compliance certification label. The tires should be warmed for a short period. Best results are obtained on smooth, dry pavement while driving at a constant speed within the posted speed limit.
AXLE/TRANSAXLE RATIO
The gear ratio of the rear axle or the final drive ratio of the transaxle must be known to select or check if the proper speedometer/odometer drive and driven gears are present. Various gear ratios are available, but usually are not a concern when dealing with speedometer/odometer concerns unless the gear ratio has been changed.
WARNING:
NEVER CORRECT SPEEDOMETER READINGS BY CHANGING GEARS UNLESS THE ODOMETER IS ALSO OFF.
DRIVE/DRIVEN GEARS
The speedometer/odometer drive gear is located inside the transmission, transaxle or transfer case and is not easily accessed for change. The driven gear rotates the speedometer cable. Rear wheel drive vehicles have several driven gears with various numbers of teeth available to correct input to the speedometer/odometer head. Front wheel drive vehicles generally do not offer different gears for correction.
GENERAL DESCRIPTION
The maximum allowable odometer system accuracy error is +/- 3.75% of the actual distance traveled. Ford Motor vehicles are well within those limits.
The speed indication is biased high, except on police vehicles with certified calibration speedometers/ odometers. As a general rule, the indicated speed is equal to or greater than the actual speed. This is intended to protect the consumer against violating speed laws. Most customer concerns are related to speedometers reading too high at true speeds between 50 MPH and 65 MPH (80 - 105 Km/h). At that speed range, the worst case errors may indicate a speed that is 10% greater than true speed.
The speedometer head is an instrument which processes information sent to it by the rotating speedometer cable. If the system components send the wrong number of revolution per mile to the speedometer head, an inaccurate speed reading and amount of distanced traveled will be displayed. Since there is no error in the fixed gear ratio of the speedometer head odometer, start by checking the accuracy of the odometer even if the customer concern indicates a speed accuracy problem. Odometer accuracy can be checked by using roads established at mile increments or a known local course. If roads with mile markers are used, a five mile stretch is recommended to allow for inaccuracies. If an error is greater than 3.75%, a change to the transmission drive/driven gear selection, tire size, or tire inflation may need attention. The odometer should be checked again to verify any corrective action. If the indicated speed error exceeds 10% between 50 MPH and 60 MPH (80 - 105 Km/h), replace the speedometer/odometer assembly.
Vehicles with transfer cases that have fluctuating readings may be due to slippage of drive gears, parts not splined or loose yoke nuts.
If the vehicle has speed control, the speed accuracy can be checked using the verified odometer vs. time. The formula is as follows:
3600 divided by TIME (seconds to cover one mile) = TRUE MPH (Km/h)EXAMPLES: 60 MPH (96 Km/h) requires 60 seconds to cover one mile
55 MPH (88 Km/h) requires 65 and 3/4 seconds to cover one mile
50 MPH (80 Km/h) requires 72 seconds to cover one mile
ARTICLE SUPERSEDED: 84-14-6, date 7/3/84
WARRANTY STATUS:
"INFORMATION ONLY"
OASIS CODES: 2300, 2310, 2400, 2500
And here is the second about replacement:
Article No.
93-12-9
06/09/93
SPEEDOMETER - ELECTRONIC INSTRUMENT CLUSTERS, PROGRAMMABLE SPEEDOMETER/ODOMETER MODULES - DIGITAL ELECTRONIC ODOMETERS - SERVICE REPLACEMENTS WITH PRE-SET VEHICLE MILEAGE
FORD:
1985-92 THUNDERBIRD
1986-93 TAURUS
1989-92 PROBE
1992-93 CROWN VICTORIA
LINCOLN-MERCURY:
1984-91 MARK VII
1984-93 CONTINENTAL
1985-92 COUGAR
1986-93 SABLE
1990-93 TOWN CAR
1992-93 GRAND MARQUIS
LIGHT TRUCK:
1986-93 AEROSTAR
1992-93 ECONOLINE, F-150-350 SERIES
1993 VILLAGER
ISSUE:
Service replacement speedometer odometers, speedometer modules, electronic instrument clusters and PSOM (programmable speedometer/odometer module) clusters, with mileage preset to the mileage displayed on the removed cluster odometer, are now available. These components must be ordered through one of three Electronic Service Centers (Two (2) U.S.; One (1) Canadian). They will be provided on an exchange basis and will not be available through the parts depots.
ACTION:
If service is required, refer to the following ordering and shipping procedure.
ORDERING PROCEDURE
U.S. DEALERS
The repair Form FPS 1878 must be filled out in sections 1A and 1B indicating the required vehicle information. A toll free phone call must be placed to the respective Electronic Service Center to relay the vehicle information:
^ Dealers who are normally serviced by the Detroit, New York and Atlanta Parts Distribution Centers should place their orders through the Eastern Electronic Service Center Call Line, 1-800-262-9606.
^ All other U.S. dealers should place their orders through the Western Electronic Service Center Call Line, 1-800-321-6969.
CANADIAN DEALERS
The repair Form 6125-2 must be filled out indicating the required vehicle information. To place an order through the Canadian Electronic Service Center, either fax the repair Form 6125-2 to FAX # 416-946-8975 or place a toll free phone call to 1-800-663-9974.
^ If the phone call or fax is placed to the Center before 4:00 p.m. on Monday through Thursday, the goal will be to provide the replacement cluster before close of business the following day.
^ If orders are placed on Friday or the day before a holiday, the cluster should be received on Monday or the day after the holiday.
The clusters are shipped pre-paid freight. Assemblies shipped to Hawaii or Alaska should be received within forty-eight hours except on Fridays or the day before holidays.
Saturday delivery is now available to dealers with Saturday operation hours. This service must be requested from the Service Center when placing the order.
SHIPPING PROCEDURES FOR REMOVED CLUSTER
Service replacement assemblies will be shipped pre-paid freight. The return freight charge will be collect. Follow the Return Shipping Instructions enclosed in the container in which the assembly was received. The removed assembly must be returned to the Electronic Service Center in the same container.
^ Ensure that the original shipping label is completely removed from the outside of the shipping container.
^ Simply affix the collect return shipping label that is supplied.
^ Place the removed assembly in the container with a copy of the memo billing from the Electronic Service Center, and the completed manufacturer's copy of Form FPS 1878 (U.S.) or FPS 6125-2 (Canada). This will ensure proper procedure so that the core charge of $300.00 will not be billed.
^ The removed assembly must be returned to the Electronic Service Center within thirty calendar days or the core charge will be billed against the dealer parts account.
HANDLING PROCEDURES FOR DIGITAL SPEEDOMETERS WITH UNKNOWN MILEAGE ACCUMULATION
To comply with regulations pertaining to the accuracy of odometers, cores will be read to determine accuracy of the reported mileage. In nearly all instances, the mileage continues to accumulate in the odometer memory chip even though the odometer is non-functional. This mileage can be verified even though it is not visible on the removed odometer.
The dealer must verify the mileage accumulated on the odometer.
^ If the mileage cannot be determined accurately, the dealer must indicate to the Electronic Service Center that the mileage is unknown.
^ In cases where the mileage is unknown, the law requires that we supply a replacement part with the mileage pre-set to "O" miles and the service odometer (circle "S") segment illuminated.
^ A sticker must be attached to the door indicating the mileage at the time of the service repair.
COST AND WARRANTY INFORMATION
The service assemblies will be billed on the monthly Dealer Parts Statement. Application is provided by part number, dealer cost and core charge. Refer to Dealer Service Manuals and the FPSD Parts and Accessories Price Listing. Repair Form FPS 1878 can be ordered from the Parts Distribution Center. Follow the normal parts allowance plus labor charge as shown in the Service Labor Time Standards Manual when requesting warranty reimbursement.
The core charge should not be entered on the warranty claim form as there will not be a charge for the core if the removed assembly is returned to the Electronic Service Center within the specified 30-day period following receipt of the replacement assembly.
DIGITAL ELECTRONIC ODOMETER REPLACEMENTS FOR UNSOLD NEW VEHICLES IN DEALER STOCK
You must use a new digital odometer for unsold new vehicles in dealer stock. Simply enter the word "Stock" for the owner name on Form FPS 1878 and identify the order as a new unsold vehicle when placing the order. Dealer handling procedures will be the same as previously outlined.
DEALER PARTS COUNTER RETAIL SALE
There will be an occasion when it will be necessary to sell digital assemblies over the parts counter. Dealers must complete Form FPS 1878 (U.S.) or 6125-2 (Canada) and provide the same information as required for a service department repair. As with warranty repairs, the dealer must verify the mileage on the removed assembly.
If the core is not received from the customer, you should charge the customer the core charge. You will be charged for the core if it is not returned. Orders will be processed the same day as received.
SPECIFIC PART NUMBER ORDERING INFORMATION
For 1984 thru 1987 Continental and all Mark VIII vehicles with an odometer concern, you can order just the NVM Module from the Service Centers (E4LY-17C269-A). If the concern is with the display, you can remove the NVM module from the cluster and order just the display (-10D922-), then install the NVM module into the replacement cluster.
NOTE:
ODOMETER MEMORY CONTROL ASSEMBLIES (-17C269-) HAVE TO BE RETURNED TO THE SERVICE CENTERS USING THE PROCEDURES AS PREVIOUSLY OUTLINED. THERE WILL BE A $300.00 CORE CHARGE IF YOU DO NOT RETURN THIS MODULE WITHIN 30 CALENDAR DAYS.
If a cluster is needed for a vehicle prior to the 1984 model year, order it from your FPSD Parts Distribution Center.
Analog PSOM components (tachometers and gauges) may now be ordered from your FPSD Distribution Center. You no longer have to order the entire cluster for those type of concerns. For any cluster with a speedometer/odometer concern, the entire cluster must be ordered from the Electronic Service Center.
When ordering an Analog PSOM cluster or 1992-93 Aerostar EIC, refer to Figures 1 and 2. The Service Center will need additional information concerning the PSOM Conversion Constant. This constant is important for correct vehicle performance. Please refer to the following procedures in your 1993 Body/Chassis Service Manuals for determining or changing the PSOM conversion constant. These procedures apply to both 1992 and 1993 vehicles equipped with PSOM clusters.
^ 1993 Aerostar, Ranger, Explorer Body/Chassis Service Manual, Page 13-02B-7, Test Step C4 through Page 13-02B-9, Test Step C7.
^ 1993 Econoline, F-150,F-250, F350, Bronco, F-super Duty Body/Chassis Service Manual, Page 13-02A-7, Test Step C4 through Page 13-02A-8, Test Step C7.
NOTE:
IF A VEHICLE HAS EITHER HAD THE TIRE SIZE/TYPE CHANGED, OR HAS HAD MODIFICATIONS TO THE REAR AXLE, IT IS NECESSARY TO CHANGE THE PSOM CONVERSION CONSTANT. THIS CONVERSION CONSTANT CAN BE CHANGED AT THE DEALERSHIP SO IT IS NOT NECESSARY TO ORDER AN ENTIRE CLUSTER IN THESE CASES.
TECHNICAL ASSISTANCE
An Electronic Instrument Cluster Help Line is available at 1-800-461-6945 to assist with any technical concerns involving the digital electronic odometer or related wiring or hardware.
A PSOM (Programmable Speedometer/Odometer Module) Cluster Help Line is available at 1-800-523-7763 to assist with any technical concerns involving the PSOM clusters or related wiring or hardware.
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 91-8-14
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 204000, 204100, 204200
Also, here is the part number you'll need: E4LY-17C269-A. This is the odometer modual. Sorry about the confussion. I answer 10 of these a day and sometimes I just make a mistake. Hope this helps, it's all I got on this.
